These 6 tees are all basically variants of 2 designs. They either have the Sonic Forces Uprising logo with the stars in a shield shape, or the Eggman Empire logo which is in the circle with the 'globe' taken over in the middle. The logos are your choice of big in the center of the tee, or smaller only on one side of the upper chest. No matter the tee color (red, black, or gray) the logos are always printed in red. These are all Sega Shop online items in 2018 and are 25 dollars each in adults sizes only.
Because the tees are pretty small in the pictures above, this is a close up of the logos so you can get a better look at them and read them. The Sonic one has "The Uprising Sonic Forces" with sheild, leaf, and star theme. They may count as 'subtle-Sonic' if they're small and only on one side of the chest area because neither features a character, just words and a logo.